The present invention relates to a process for producing piperidinecarboylic acid amide derivatives useful as serotonin antagonists, antithrombocytic agents or intermediates for them.
Ischemic diseases such as myocardial infarction and cerebral infarction are concerned with thrombi. In particular, it is considered that thrombocytes play an important part in the formation of thrombosis in the arteries. Thus, various antithrombocytic agents were developed. For example, Japanese Patent Unexamined Published Application (hereinafter referred to as "J. P. KOKAI") No. Hei 8-3135 reported compounds usable as the serotonin antagonists or antithrombocytic agents. The following process for producing compounds having a piperidinecarboxylic acid amide structure, among those compounds, is disclosed therein. ##STR1##
However, 2-aminoethyl bromide used in this process is a poisonous substance, and carcinogenic aziridine is possible to be formed by the reactions. Thus, this process is not preferred for the production on an industrial scale. Under these circumstances, the development of a safer process has been demanded.